‘Transient electronics’ that dissolve when triggered
April 8, 2014
Reza Montazami, an Iowa State University assistant professor of mechanical engineering, is developing technology he calls “transient materials” or “transient electronics” — special degradable polymer composite materials designed to quickly and completely melt away when a trigger is activated.
A medical device, once its job is done, could harmlessly melt away inside a person’s body. Or, a military device could collect and send its data and then dissolve away, leaving no trace of an intelligence mission. Or, an environmental sensor could collect climate information, then wash away in the rain.
The research team he’s leading, for example, is developing these degradable materials as platforms for electronic components. The team has also built and tested a degradable antenna capable of data transmission.
New transient polymer composite developed at Advanced Materials Laboratory at Iowa State University is tested. A blue light-emitting diode is mounted on a clear polymer composite base with the electrical leads embedded inside. Add a drop of water and the base and wiring begin to melt away. Before long, the light goes out and a second drop of water degrades what little is left.
How it works
Describing the research in a paper in Advanced Functional Materials, the researchers mentioned that the polymer composites consists of different ratios of gelatin or sucrose integrated with poly(vinyl alcohol) (PVA) matrices. The also demonstrated that “dissolution and transiency of the polymer composites could be retarded or enhanced by addition of gelatin or sucrose at different ratios, respectively.
The researchers have developed and tested transient resistors and capacitors. They’re now working on transient LED and transistor technology, said Montazami.
Just think, he said, if you lose your credit card, you could send out a signal that causes the card to self-destruct. Or, sensors programmed to degrade over certain times and temperatures could be stored with food. When the sensors degrade and stop sending a signal, that food is no longer fresh. Or, when soldiers are wounded, their electronic devices could be remotely triggered to melt away, securing sensitive military information.
“The technology would be useful for any application in which sensitive data are used,” Montazami explained to KurzweilAI. He mentioned military electronic equipment, credit cards, and passports, and “any application in which the electronic device is to be used for a defined period of time. Examples: bioelectronics, implantable electronics, environmental monitoring applications, etc.
“There are very few research groups working on similar technology,” he added. “Our technology is different in the membranes we synthesized and use, and the way electronic components vanish. Prototypes are expected within several months; commercialization may take few years depending on the interest of investors etc.
Researchers at the U.S. Department of Energy’s Ames Laboratory and Washington State University’s School of Mechanical and Materials Engineering were also involved in the study.
The research has been supported by startup funds from Iowa State. He’s pursuing grants to support additional projects.
Abstract of Advanced Functional Materials paper
Controlled degradation and transiency of materials is of significant importance in the design and fabrication of degradable and transient biomedical and electronic devices and platforms. Here, the synthesis of programmable biodegradable and transient insulating polymer films is reported, which have sufficient physical and chemical properties to be used as substrates for the construction of transient electronics. The composite structure can be used as a means to control the dissolution and transiency rate of the polymer composite film. Experimental and computational studies demonstrate that the addition of gelatin or sucrose to a PVA polymer matrix can be used as a means to program and either slow or enhance the transiency of the composite. The dissolution of the polymer composites are fitted with inverse exponential functions of different time constants; the lower time constants are an indication of faster transiency of the polymer composite. The addition of gelatin results in larger time constants, whereas the addition of sucrose generally results in smaller time constants.